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RAND USR that doesn't work in emulators and clonesEons ago, I "discovered" a strange RANDOMIZE USR. This is it: [b]RANDOMIZE USR 46578[/b] Using it on a genuine ZX Spectrum rubber key or Plus model,…
... I "discovered" a strange RANDOMIZE USR. This is it:
... [b]RANDOMIZE USR 46578[/b]
USR in an emulator in ... happening here. The RAND USR proposed just begins executing ... parameter for the RAND USR, the pattern doesn't ... -
(part of) screen to UDGHere is a routine to copy a Y,X-position on screen to a UDG. 0<=y<=23 0<=x<=31 144<=udg<=165 (UDG "A" to UDG "U") [code] ; start code with ; PRINT …
Here is a routine to copy a Y,X-position on screen to a UDG.
0 -
Rambo (improved BUGFIX)An improved BUGFIX was provided for game [URL="http://www.worldofspectrum.org/infoseekid.cgi?id=0004010"]Rambo[/URL], please replace the "known error…
... by executing instruction LDIR (setting BC to zero), then instruction LDI ... BC to $FFFE), then another instruction LDIR after setting only C register ... instead of BC, as follows:
[CODE ... -
Cobra (improved BUGFIX)This is an improved BUGFIX for game [URL="http://www.worldofspectrum.org/infoseekid.cgi?id=0000996"]Cobra[/URL], please replace the "known errors" de…
... :
[CODE]
95fe: ld bc,$3f28
9601: ld a ...
9602: in a,($ff) ; register 'A' always set to $FF ... ]
95fe: ld bc,$0300
9601: dec bc
9602: ld ... -
BC's Quest for Tires code sheet missingSpeaking of [URL="http://www.worldofspectrum.org/forums/showthread.php?t=35314"]missing code sheets[/URL], it appears the sheet for [URL="http://www.…
... .org/infoseekid.cgi?id=0000477"]BC's Quest for Tires[/URL ... -
Keys redefine routine and key check.I have written some asm code which allows me to redefine keys (for a game etc.), and also allows me to be able to check any keypresses for the redefi…
... ,0: LET l = USR startaddress: REM will return ... )
; or BC holds the address of the ... (/me hopes)
ld bc,key_up_port ; return the keys ...
; -----------------------------------------------
delay: ld bc,32768
ld a,0 ... -
saving part of a BASIC programHere's a short routine to save part of a BASIC program. The idea is that it can be merged into a program and then used to save sub-routines, etc. to …
... /> 9995 RANDOMIZE ap: LET bc=l+USR (vars+29): STOP
9996 ... -
Is it possible to access the +3 disk drive via m/c in USR0 mode?Is it possible to access the disk drive of the +3 via m/c +3DOS calls when running in USR0 mode? I ask because I'm having an awful lot of trouble ge…
... ),sp ; 36864
ld bc,$7ffd
ld a,($5b5c ... a CLEAR 49050 before PRINT USR 48796)
ei ; ... here
ld bc,1
here push bc
... /> out (c),a
pop bc
ei
...
di
ld bc,$7ffd
ld a,($5b5c ... -
Canny use of the 'r' register?Seeing Sokurah's code in the [URL="http://www.worldofspectrum.org/forums/showthread.php?p=583188#post583188"]crunch sound thread[/URL] has made me th…
... me think about the r register.
I've used ... crafty uses for the r register? -
BREAK from GOSUBHere's another one. Just in case you wanted to break out of multiple GOSUB levels with a single command, here's a routine to do it, tested on all mod…
... BASIC with RANDOMIZE n+USR retsub, where 'n' ... : EXX ; 217
POP BC ; 193
POP HL ; ... ;$1B76 STMT_RET
PUSH BC ; 197 ;restore STMT_RET
Procrustean PrintingHere's a short routine to manage printing of text with command tokens, to avoid messing up the screen when they are expanded. It just prints as many …
... equ $2da2 ;from calculator stack: BC
FPTOA: equ $2dd5 ;from ... ,GETARG
call FPTOBC ;BC=addr
ld h,b ... ;JP address
;PRINT USR stack,string_expression,max_length,substr;
Indirect Variable AssignmentHere's another wacky routine. This allows assignment of values to variables where the source & destination variables can themselves be defined in var…
... v$,v
10 PRINT USR id,"val"+CHR$ (a+64 ... ),"=",v;
11 PRINT USR id,v$,"=",v+VAL ("val ... /> The syntax is:
;PRINT USR indirect,arg1,op,arg2;
;Indirect Variable Assignment
;PRINT USR indirect,arg1,op,arg2;
Undefine functionHere's a routine to selectively remove variables from the VARS area and reclaim the space. This can be done partially from BASIC already by assigning…
...
ld sp,hl ;undo USR
ld ix,0
push ix
pop bc
ld b,c ;B ... ;variable name address
push bc ;variable name length
call ...joining lines of BASICDue to overwhelming demand - well, one demand - well, more of a suggestion, really - here's a routine to join together lines of BASIC. The vertical c…
... new. LOAD at 65023, RANDOMIZE USR 65136 to enable, 65146 to ... HL,(23643) ;K_CUR
LD BC,31
CP 10 ;cursor ...
inc bc
inc bc
inc bc
inc bc ;BC=2nd line ...28-character wide multicolour(ish) on 48k SpectrumLong-time lurker here... I've always been interested in rainbow effects on the 48k Spectrum, mainly from a perspective of "Just what [I]would [/I]ha…
... used PUSHes of three register pairs, HL, BC and DE - ... add AF to the register pairs that could be ... EXX to swap the register values that were being ... contention-free period
PUSH BC
PUSH DE
PUSH BC
PUSH DE
Help pleeease "Proving Emulator OpCode flags are correct"So I had a cunning plan... I wanted to write a test harness for Emulators that could "prove" that all opcode flags were correct. I wanted something m…
... fAddr,F
200 RANDOMIZE USR mcAddr
210 POKE lAddr ... D,0 //dAddr
PUSH BC
POP AF
ADC ...simplest method to pass a string to m/code?The statement "RANDOMIZE numvar+USR mc" is a simple way of passing a single numeric parameter to a m/c routine, as mc can retrieve numvar from the to…
... be:
* PRINT USR mc,s$;: but that needs ... * DEF FN m(s$)=USR mc: LET bc=FN m(s$): whereby ... br /> * RANDOMIZE CODE "s"+USR mc: but that needs some ... syntactically incorrect "RANDOMIZE s$+USR mc"? I was wondering ... like "RANDOMIZE LEN s$+USR mc" might leave s ...What's wrong with this code ?OK, working my way through Jonathan Cauldwells 'How To' tome and I can't get the following to run in either spin or basin. ( iused the assembler in b…
... />
when run using RANDOMIZE USR location i just get 'B ... new coordinates.
ld bc,63486 ; keyboard row 1-5 ...Jelly-Vision!As threatened in the "'Spectrum Play' Error" thread, here's a ruff'n'reddy interrupt driven full screen wobbling routine which has no practical use w…
... 23681,254: RANDOMIZE USR 33001
; stop : RANDOMIZE USR 32994
< ... /> jr z,INSCROLL
push bc
push de[/color]
xor 1
ld bc,6144-256
jr nz ...Ideas for speeding up this BASIC routine?This loop can take up to 2 minutes to run, depending upon the content of the screen being scanned, about 70% of that time being taken up by lines 105…
... )? Don't worry about the USR calls, they don't take ... POKE 23678,y: LET y=USR toprow:
IF NOT y ...Using R as a loop counterThis is just something silly I've found a while back. xD [b][How-to][/b] Setup your routine like this:[code] ld a,X ;see below ld r,a loop ;your …
... border.[code] di
ld bc,#0405 ;b=LoopN, c=Rinc ... loop using an 8-bit register, yay!
So yeah ...multi-scroll m/c subroutine for BASICArising from recent posts, here's a scrolling routine that will manage multiple left/right scrollings for any (sensible) line width or step; (ie. whe…
Arising from recent posts, here's a scrolling routine that will manage multiple left/right scrollings for any (sensible) line width or step; (ie. where width isUSR 0I've heard a lot about loading a program in USR 0 (and yes, I know how to do it - "RANDOMIZE USR 0" in 128 BASIC). What I want to know is: What is th…
I've heard a lot about loading a program in USR 0 (and yes, I know how to do it - "RANDOMIZE USR 0" in 128 BASIC). What I want to know is: What is the point of loading a program in USR 0 mode, and what does it actually DO?SpecBAS article in The Register todayDunny's SpecBAS (for the Raspberry Pi) got a write-up in The Register today: [url]http://www.theregister.co.uk/2012/11/13/sinclair_basic_for_raspber…
Dunny's SpecBAS (for the Raspberry Pi) got a write-up in The Register today:
[url]http://www.theregister.co.uk/2012/11/13/sinclair_basic_for_raspberry_pi/[/url]Optimisations in Exomizer Z80 decrunch codeThis is the 163 bytes old code (simple and optimized): [CODE] ld iy, exo_mapbasebits ld a, 128 ld b, 52 push de exo…
... br /> push ix
pop bc ;bc=lenght
ldir
pop ... avoiding the use of AF' register pair.
I ... br /> push ix
pop bc ;bc=lenght
ldir
pop ...Elliptical ChallengeSubsequent to the recent "Graph Plot" thread, I wrote this general purpose ellipse drawing routine which will plot (although it doesn't actually use …
... ]
LET e$="hkab"+STR$ USR ellipse
h = CHR$ ... ld de,(STKENDO)
ld bc,20
ldir ;copy 0 ... 2dd5 ;FP_TO_A
pop bc
push bc ;C =x
ld ...Author of The Hobbit featured on The RegisterSpotted another ZX Spectrum-related on The Register today: an article featuring the personal history of Veronika Megler (yes, a woman), one of the pr…
... ZX Spectrum-related on The Register today: an article featuring the ...Problem with Page 7I've been experimenting with running code in page 7 (+3) from BASIC and I seemed to have got it sorted out but then it all went wrong. Firstly, I tr…
... ]
So I had "LD BC,$ffff : RET" in page 7 ... : OUT 32765,16+7: PRINT USR 65368:
POKE 23388,16 ...I thought I'd give assembly a goAnd well being an absolute newb,I'm absolutely useless.I need your help. I thought I'd give this a go in zxspin [url]http://chuntey.wordpress.com/20…
... did this and typed ld bc,0 to line 4
USR 33000
i end up ...
